Self-winding watches



June 28, 96() P. BEGUIN 2,942,486

SELF-WINDING WATCHES Filed Feb. 4, 1958 'lll/Av1 Ilm/1111.

'N4-winmix 13 Pfam BEGUIN INVENTOR United States Patent O "ice y 2,942,486 SELF-WINDING WATCHES Pierre Bguin, Waldenburg, Switzerland, assignor to Revue Fabriques dHorlogerie Thommen S.A., Waldenburg, Switzerland, a Swiss company Filed Feb. 4, 1958, Ser. No. 713,174

Claims priority, application Switzerland Feb. 13, 1957 4 Claims. (Cl. 'I4- 125) My present invention relates to a selfwinding watch of which the winding mechanism comprises an oscillating mass destined to impart, by means of a control cam, a reciprocating movement to a transmission element in order to turn, by means of two pawls associated to the latter, a ratchet wheel in the sense of winding the watch mam spring.

As disclosed by the present invention, this automatic watch is characterized by the fact that the transmission element and the pawls are disposed in the same plane, the connection between said element on one hand and the pawls on the other hand being effected by articulation means which also are situated in said plane.

Such a selfwinding mechanism or automatic movement has the advantage of being very simple and of requiring little headroom, besides being very sturdy.

One form of the invention and a modication are shown, by way of example, in the drawing, in which:

Fig. 1 is a longitudinal section of the selfwinding mechanism,

Fig. 2 is a plan view thereof, certain of the .parts shown in Fig. l having been omitted, and

Fig. 3 is a plan view of a modication.

The selfwinding mechanism shown in Figs. 1 and 2 comprises a control cam in the form of a heart 1 rotatably mounted, by means of a tubular hub 1a, on a pivot 2a which is an integral .part of a bridge 2 which in turn is xed to the movement plate. To the upper portion of hub 1a is xed an eccentric plate 3 which constitutes the oscillating mass of the automatic movement. Control cam 1 is engaged in a rectangular opening 4a of a slide in the form of a stamped-out plate 4 disposed in the same plane as said cam and serving as transmission element. In said plane is also situated the ratchet wheel 5 of which the axle pin carries a pinion 6 meshing with the barrel ratchet wheel 7. Slide 4 is guided in the sense of a line passing through the centers of rotation of cam 1 and ratchet wheel 5, and to such end is provided, at its end remote from ratchet wheel 5, with a guide slot 4b disposed on said line. In slot 4b is loosely engaged a shouldered pin 8 Xed to bridge 2, which shoulder serves at the same time as bearing surface for slide 4. At its other end, slide 4 is provided with two arms which end in disc-like portions 4c and at their centers carry pins 9, for example jewel pins, which at their lower ends bear on plates 10 of polished steel fixed to bridge 2. A knob 4d integral with slide 4 contacts the guide surface 11a of a bridge 11 (Fig. 1) which for such purpose may be set for exam-ple with jewels or beryllium bronze. Cam 1, when rotating, imparts slide 4 with a reciprocating movement whereby in turn are actuated two opposite pawls 12 situated in the plane of the slide and of which the tips are engaged in the teeth of ratchet wheel 5. At their other ends, said pawls are provided with a circular opening in which is engaged a projecting disc-like portion 4c of slide 4. Said openings and projecting portions thus form articulating means between the pawls 12 and slide 4,

2,942,486 Patented June 28, 1960 Which means are disposed in the common plane of said slide and pawls. When slide 4 moves back and forth, the pawls 12 entrained thereby actuate through their tips the ratchet wheel 5 which thus is always turned in the same direction, namely in the sense of winding the watch mainspring. The pawls 12 are provided, on one side and the other of the projecting portions 4c of slide 4, with stop dogs 12a and 12b. A U-shaped leaf spring 13` fixed in a cross-groove or" slide 4, abuts with the ends of its two legs against the external dogs 12b of the pawls 12 in order to hold t-he pawl tips in engagement with the teeth of -ratchet wheel 5.

To facilitate the assembly of the mechanism, the stop dogs 12a limit, through their abutment against the transmission element 4, the angular movement of the pawls, thus permitting same to remain attached to said element onlyunder the tension of spring 13.

In the winding mechanism described, the transmission element in the form of plate 4, cam 1, ratchet wheel 5, the pawls 12 and the articulating means between the pawls 12 and element 4 are situated in the same plane. Should it be necessary, ratchet wheel 5 could be disposed outside of said plane in order to provide more room to other parts of the mechanism. In such case, the pawl tips would be brought back into said plane by folding. The same result would be obtained by using pawls of which the tips are thicker than the body.

In the modification shown in Fig. 3, the articulating means between slide 14 and the pawls 15 are constituted by circular openings in the arms 14a of slide 14 and by projecting portions 15a of polygonal form and integral with the pawls 15, which are engaged in said openings so as to be in slide Contact therein What I claim as new is:

l. In a seifwinding mechanism for a. watch, the combination of a ratchet mechanism consisting essentially oi a ratchet wheel and two ratchet pawls bearing on said ratchet wheel and coplanar therewith on opposite edges oi said ratchet wheel, and a driving mechanism for said ratchet wheel consisting essentially of a at transmission element coplanar with said ratchet wheel and having two arms thereon on the ends of which said ratchet pawls are pivotally mounted, said transmission element having an aperture therein, and a at cam coplanar with said transmission element in said aperture and engaging said transmission element for reciprocating said transmission element, whereby the ratchet mechanism and driving mechanism have an edge profile which is substantially the thickness of said element.

2. The combination as claimed in claim 1 in which the pivotal mounting of said pawls on said transmission element comprises a flat circular element on the ends of the arms of said transmission element, said pawls having circular openings in the ends thereof rotatably positioned around said circular elements.

3. The combination as claimed in claim l in which the pivotal mounting of said pawls on said transmission element comprises polygonal elements on the ends of said pawls, and open sided circular apertures on the ends of the arms of said transmission element within which said polygonal elements rotate.

4. The combination as claimed in claim 1 in which each pawl has two projections on the end opposite to the ratchet wheel. engaging end, said projections diverting from each other and having the pivotal mounting `for the pawl therebetween, and spring means on said transmission member and bearing on one arm of each pawl and urging said pawls to pivot toward each other, the other arms on said pawls engaging said transmission member as limiting stops for the pivotal movement of said pawl.

(References on following page) i References Cited in the file of this patent UNITED STATES PATENTS Mitchell Aug. 16, 185,9 Schurmann Apr. 6, 1880 Campen Sept. 11, 1883 Westinghouse Dec. 26, 1916 Wasson Nov. 25, 1941 Raskin May 8, 1951 Mitchell Nov. 18, 1952 Hooker Feb. 10, 1953 Iaros Feb. 10, 1953 Langel Dec. 7, 1954 FOREIGN `PATENTS France Aug. 18, 1903 Germany Jan. 25, 1907 Switzerland Iune 5, 1948 Great Britain June 7,'1950 

